<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    #biaoti{
      color: red;
      height: 50%;
    }
    .-P1{
      color: yellow;
    }
    p{
      color: #000000;
    }
  </style>
</head>
<body>
  <h1 id="biaoti">你好</h1>
  <p class="-P1">我是p标签</p>
  <p>我很好</p>

</body>
</html>